The overall objectives of this research project are: a. To determine the cell type which expresses Ir gene control of specific immune responses; b. To map immune response genes with respect to other functions of the H-2 complex; c. To isolate and characterize the Ir-1 gene product; d. To determine the role of histocompatibility-linked Ir genes in susceptibility or resistance to infectious, neoplastic, and autoimmune diseases. BIBLIOGRAPHIC REFERENCES: McDevitt, H.O., Oldstone, M.B.A., and Pincus, T., Histocompatibility-linked genetic control of specific immune responses to viral infection. Transpl. Rev. 19:209-225, 1974; Hammerling, C.J., Mauve, G., Goldberg, E., and McDevitt, H.O., Tissue distribution of Ia antigens: Ia on spermatozoa, macrophages, and epidermal cells. Immunogenetics I:428-437, 1975.